Oldest chelicerate shows early fangs

Researchers describe Megachelicerax cousteaui, a three‑inch, 500‑million‑year‑old arthropod from Utah with chelicerae where antennae normally are, interpreted as the earliest known chelicera (mouthparts that in spiders became fangs). The fossil, published in Nature, pushes the chelicerate lineage back about 20 million years and suggests complex feeding anatomy arose during the mid‑Cambrian. — Revising the timing of a major arthropod lineage affects public and scientific narratives about how and when key anatomical innovations (like venomous fangs) evolved and highlights that novelty alone doesn’t guarantee immediate ecological dominance.